The generalized Kadanoff-Baym ansatz with initial correlations
Karlsson, D., van Leeuwen, R., Perfetto, E., & Stefanucci, G. (2018). The generalized Kadanoff-Baym ansatz with initial correlations. Physical Review B, 98(11), Article 115148. https://doi.org/10.1103/PhysRevB.98.115148
Published inPhysical Review B
©2018 American Physical Society
Within the nonequilibrium Green’s function (NEGF) formalism, the generalized Kadanoff-Baym ansatz (GKBA) has stood out as a computationally cheap method to investigate the dynamics of interacting quantum systems driven out of equilibrium. Current implementations of the NEGF-GKBA, however, suffer from a drawback: real-time simulations require noncorrelated states as initial states. Consequently, initial correlations must be built up through an adiabatic switching of the interaction before turning on any external field, a procedure that can be numerically highly expensive. In this work, we extend the NEGF-GKBA to allow for correlated states as initial states. Our scheme makes it possible to efficiently separate the calculation of the initial state from the real-time simulation, thus paving the way for enlarging the class of systems and external drivings accessible by the already successful NEGF-GKBA. We demonstrate the accuracy of the method and its improved performance in a model donor-acceptor dyad driven out of equilibrium by an external laser pulse. ...
PublisherAmerican Physical Society
Publication in research information system
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Related funder(s)Academy of Finland
Funding program(s)Postdoctoral Researcher, AoF
Additional information about fundingD.K. acknowledges the Academy of Finland for funding under Project No. 308697, and the Finnish Grid and Cloud Infrastructure for computational resources (urn:nbn:fi:researchinfras-2016072533). G.S. and E.P. acknowledge EC funding through the RISE Co-ExAN (Grant No. GA644076). E.P. also acknowledges funding from the European Union project MaX Materials design at the eXascale H2020-EINFRA-2015-1, Grant Agreement No. 676598 and Nanoscience Foundries and Fine Analysis-Europe H2020-INFRAIA-2014-2015, Project No. 654360. ...
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